Lead removal from aqueous solution by employing natural brucite

The effect and mechanism of the removal of Pb²⁺ from an aqueous solution by using brucite as the adsorbent were studied.It was revealed that the increase in pH of brucite suspension, as a result of the release of magnesium hydroxide into the suspension,leads to a sharp rise of the adsorption amount of Pb²⁺ on brucite. The synergism of buffering and adsorption capacities of brucite is responsible for the removal of Pb²⁺ from the aqueous solution. The coexistence of Cu²⁺ with Pb²⁺ causes a decrease of their adsorption on brucite due to a competition for surface sites and brucite exhibits a higher adsorption capacity for Pb²⁺ than for Cu²⁺. The percentage adsorption of Pb²⁺ on brucite could reach 96.38%, 97.20% and 94.09% respectively with the initial pH of the suspension pH_i = 1.76 (initial Pb²⁺ concentration [Pb²⁺]_i = 20 μmol/L), 1.82 ([Pb²⁺]_i = 100 μmol/L) and 1.84 ([Pb²⁺]_i = 500 μmol/L). It was concluded that brucite is a very efficient mineral adsorbent for Pb²⁺ removal from polluted acidic water.